TF1 1/2″ Specialty Recreation Self Sealing Water Tank Adapter FittingThe TF1 fitting is designed to not require access into the inside a polyethylene tank when installing. Simply make a 7/8″ hole, then insert the fitting with the interior nut, and the teeth on the nut allow you to tighten the fitting from the outside.Installation DirectionsFirst, drill a 7/8″ hole at the desired location. Once that is done, back the nut off to the end of the threads, and insert the fitting into the hole at a 45 degree angle. It should snap into place. The last step is to pull down on the fitting and slowly turn clockwise until it is snug and the O ring is seated.Additional InfoCut-Out Diameter7/8″Barb Fitting1/2″Required Tank MaterialPolyethylene